Lettuce variety 45-149 RZ

ABSTRACT

The present invention relates to a  Lactuca sativa  seed designated 45-149 RZ, which exhibits resistance to downy mildew ( Bremia lactucae ) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistance to currant-lettuce aphid ( Nasonovia ribisnigri ), moderately glossy leaves, and a medium head size. The present invention also relates to a  Lactuca sativa  plant produced by growing the 45-149 RZ seed. The invention further relates to methods for producing the lettuce cultivar, represented by lettuce variety 45-149 RZ.

INCORPORATION BY REFERENCE

All documents cited or referenced herein (“herein cited documents”), andall documents cited or referenced in herein cited documents, togetherwith any manufacturer's instructions, descriptions, productspecifications, and product sheets for any products mentioned herein orin any document incorporated herein by reference, are herebyincorporated herein by reference, and may be employed in the practice ofthe invention.

FIELD OF THE INVENTION

The present invention relates to a new iceberg lettuce (Lactuca sativa)variety which exhibits resistance to downy mildew (Bremia lactucae)races Bl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistanceto currant-lettuce aphid (Nasonovia ribisnigri), moderately glossyleaves, and a medium head size.

BACKGROUND OF THE INVENTION

All cultivated forms of lettuce belong to the highly polymorphicspecies, Lactuca sativa, which is grown for its edible head and leaves.As a crop, lettuces are grown commercially wherever environmentalconditions permit the production of an economically viable yield.

Lactuca sativa is in the Cichoreae tribe of the Asteraceae (Compositae)family. Lettuce is related to chicory, sunflower, aster, scorzonera,dandelion, artichoke and chrysanthemum. Sativa is one of about 300species in the genus Lactuca.

Lettuce cultivars are susceptible to a number of pests and diseases suchas downy mildew (Bremia lactucae). Every year this disease leads tomillions of dollars of lost lettuce crop throughout the world. Downymildew (Bremia lactucae) is highly destructive of lettuce grown atrelatively low temperature and high humidity. Downy mildew is caused bya fungus, Bremia lactucae, which can be one of the following strains:NL1, NL2, NL4, NL5, NL6, NL7, NL10, NL12, NL13, NL14, NL15, NL16, Bl:17,Bl:18, Bl:20, Bl:21, Bl:22, Bl:23, Bl:24, Bl:25, Bl:26, Bl:27, Bl:28(Van Ettekoven, K. et al., “Identification and denomination of ‘new’races of Bremia lactucae,” In: Lebeda, A. and Kristkova, E (eds.),Eucarpia Leafy Vegetables, 1999, Palacky University, Olomouc, CzechRepublic, pp. 171-175; Van der Arend et al. “Identification anddenomination of “new” races of Bremia lactucae in Europe by IBEB until2002.” In: Van Hintum, Th et al. (eds.), Eucarpia Leafy VegetablesConference 2003, Centre for Genetic Resources, Wageningen, TheNetherlands, p. 151; Plantum NL (Dutch association for breeding, tissueculture, production and trade of seeds and young plants), IBEB pressrelease, “New race of Bremia lactucae Bl:27 identified and nominated”,May 2010; Plantum NL (Dutch association for breeding, tissue culture,production and trade of seeds and young plants), IBEB press release,“New race of Bremia lactucae Bl:28 identified and nominated”, March2011), Ca-I, Ca-IIA, Ca-IIB, Ca-III, Ca-IV (Schettini, T. M., Legg, E.J., Michelmore, R. W., 1991. Insensitivity to metalaxyl in Californiapopulations of Bremia lactucae and resistance of California lettucecultivars to downy mildew, Phytopathology 81(1). p. 64-70), and Ca-V,Ca-VI, Ca-VII, Ca-VIII (Michelmore R. & Ochoa. O. “Breeding CrispheadLettuce.” In: California Lettuce Research Board, Annual Report2005-2006, 2006, Salinas, Calif., pp. 55-68). Also new strains appear,which are overcoming resistance gene combinations in present varieties.An example is strain F837 which is overcoming the Bremia-resistance inthe varieties “Design”, “Bedford” and the IBEB-test line “RYZ-2164”.Another example is strain USA927 which is overcoming theBremia-resistance in the variety “Kibrille” and the IBEB-test line“RYZ-910457”. New strains can be described by a sextetcode based onresistance test results on a set of 25 publicly available lettuce lines(IBEB press release May 2010. F837 has sextetcode EU-B 63-63-13-11 andUSA927 has sextetcode 57-63-02-05.

Downy mildew causes pale, angular, yellow areas bounded by veins on theupper leaf surfaces. Sporulation occurs on the opposite surface of theleaves. The lesions eventually turn brown, and they may enlarge andcoalesce. These symptoms typically occur first on the lower leaves ofthe lettuce, but under ideal conditions may move into the upper leavesof the head. When the fungus progresses to this degree, the head cannotbe harvested. Less severe damage requires the removal of more leavesthan usual, especially when the lettuce reaches its final destination.

Of the various species of aphids that feed on lettuce, thecurrant-lettuce aphid (Nasonovia ribisnigri) is the most destructivespecies because it feeds both on the leaves of the lettuce as well asthe heart of the lettuce, making it difficult to control withconventional insecticides. The lettuce aphid feeds by sucking sap fromthe lettuce leaves. Although direct damage to the lettuce may belimited, its infestation has serious consequences because the presenceof aphids makes lettuce unacceptable to consumers.

Vegetables are generally considered as healthy food. Both consumers aswell as producers benefit from an increase of vegetable consumption.Higher vegetable consumption can be promoted by education, marketing,and improvement of certain product traits, like taste, aroma, and visualattractiveness. Visual attractiveness of iceberg lettuce heads ispromoted by absence of leaf damage and related discolorations and afresh, shiny green color. Between iceberg varieties there exists geneticvariability in the glossiness of the head leaves. With respect to visualattractiveness of iceberg lettuce heads moderately glossy green headleaves are desirable over dull green head leaves.

Citation or identification of any document in this application is not anadmission that such document is available as prior art to the presentinvention.

SUMMARY OF THE INVENTION

There exists a need for an iceberg lettuce variety which exhibits acombination of traits including resistance to downy mildew (Bremialactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927,resistance to currant-lettuce aphid (Nasonovia ribisnigri), moderatelyglossy leaves, and a medium head size.

The present invention addresses this need by providing a new type oficeberg lettuce (Lactuca sativa) variety, designated 45-149 RZ. Lettucecultivar 45-149 RZ exhibits a combination traits including resistance todowny mildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, andstrains F837 and USA927, resistance to currant-lettuce aphid (Nasonoviaribisnigri), moderately glossy leaves, and a medium head size.

The present invention provides seeds of iceberg lettuce cultivar 45-149RZ, which have been deposited with the National Collections ofIndustrial, Marine and Food Bacteria (NCIMB) in Bucksburn, Aberdeen AB219YA, Scotland, UK and have been assigned NCIMB Accession No. 42131.

In one embodiment, the invention provides a lettuce plant which mayexhibit a combination of traits including resistance to downy mildew(Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 andUSA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size, representative seed ofwhich have been deposited under NCIMB Accession No. 42131.

In one embodiment, the invention provides a lettuce plant designated45-149 RZ, representative seed of which have been deposited under NCIMBAccession No. 42131.

In an embodiment of the present invention, there also is provided partsof a lettuce plant of the invention, which may include parts of alettuce plant exhibiting a combination of traits including resistance todowny mildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, andstrains F837 and USA927, resistance to currant-lettuce aphid (Nasonoviaribisnigri), moderately glossy leaves, and a medium head size, or partsof a lettuce plant having any of the aforementioned resistance(s) and acombination of traits including one or more morphological orphysiological characteristics tabulated herein, including parts oflettuce variety 45-149 RZ, wherein the plant parts are involved insexual reproduction, which include, without limitation, microspores,pollen, ovaries, ovules, embryo sacs or egg cells and/or wherein theplant parts are suitable for vegetative reproduction, which include,without limitation, cuttings, roots, stems, cells or protoplasts and/orwherein the plant parts are tissue culture of regenerable cells in whichthe cells or protoplasts of the tissue culture are derived from a tissuesuch as, for example and without limitation, leaves, pollen, embryos,cotyledon, hypocotyls, meristematic cells, roots, root tips, anthers,flowers, seeds or stems. The plants of the invention from which suchparts may come from include those wherein representative seed of whichhas been deposited under NCIMB Accession No. 42131.

In another embodiment there is a plant grown from seeds, representativeseed of which having been deposited under NCIMB Accession No. 42131. Ina further embodiment there is a plant regenerated from theabove-described plant parts or regenerated from the above-describedtissue culture. Advantageously such a plant may have morphologicaland/or physiological characteristics of lettuce variety 45-149 RZ and/orof a plant grown from seed, representative seed of which having beendeposited under NCIMB Accession No. NCIMB 42131—including withoutlimitation such plants having all of the morphological and physiologicalcharacteristics of lettuce variety 45-149 RZ and/or of plant grown fromseed, representative seed of which having been deposited under NCIMBAccession No. NCIMB 42131. Advantageously, such a plant demonstrates thetraits of resistance to downy mildew (Bremia lactucae) races Bl:1-28Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size. Accordingly, in still a further embodiment,there is provided a lettuce plant having all of the morphological andphysiological characteristics of lettuce variety 45-149 RZ,representative seed of which having been deposited under NCIMB AccessionNo. 42131. Such a plant may be grown from the seeds, regenerated fromthe above-described plant parts, or regenerated from the above-describedtissue culture. A lettuce plant having any of the aforementionedresistance(s), and one or more morphological or physiologicalcharacteristics recited or tabulated herein, and a lettuce plantadvantageously having all of the aforementioned resistances and thecharacteristics recited and tabulated herein, are preferred. Parts ofsuch plants—such as those plant parts above-mentioned—are encompassed bythe invention.

In one embodiment, there is provided progeny of lettuce cultivar 45-149RZ produced by sexual or vegetative reproduction, grown from seeds,regenerated from the above-described plant parts, or regenerated fromthe above-described tissue culture of the lettuce cultivar or a progenyplant thereof, representative seed of which having been deposited underNCIMB Accession No. 42131. The progeny may have any of theaforementioned resistance(s), and one or more morphological orphysiological characteristics recited or tabulated herein, and a progenyplant advantageously having all of the aforementioned resistances andthe characteristics recited and tabulated herein, are preferred.Advantageously, the progeny demonstrate the traits of resistance todowny mildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, andstrains F837 and USA927, resistance to currant-lettuce aphid (Nasonoviaribisnigri), moderately glossy leaves, and a medium head size.

Progeny of the lettuce variety 45-149 RZ may be modified in one or moreother characteristics, in which the modification is a result of, forexample and without limitation, mutagenesis or transformation with atransgene.

In still another embodiment, the present invention provides progeny oflettuce cultivar 45-149 RZ produced by sexual or vegetativereproduction, grown from seeds, regenerated from the above-describedplant parts, or regenerated from the above-described tissue culture ofthe lettuce cultivar or a progeny plant thereof, in which theregenerated plant shows a combination of traits including resistance todowny mildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, andstrains F837 and USA927, resistance to currant-lettuce aphid (Nasonoviaribisnigri), moderately glossy leaves, and a medium head size.

In still a further embodiment, the invention may comprise a method ofproducing a hybrid lettuce seed which may comprise crossing a firstparent lettuce plant with a second parent lettuce plant and harvestingthe resultant hybrid lettuce seed, in which the first parent lettuceplant or the second parent lettuce plant may be a lettuce plant of theinvention, e.g. a lettuce plant having a combination of traits includingresistance to downy mildew (Bremia lactucae) races Bl:1-28 Ca-I toCa-VIII, and strains F837 and USA927, resistance to currant-lettuceaphid (Nasonovia ribisnigri), moderately glossy leaves, and a mediumhead size and one or more morphological or physiological characteristicstabulated herein, including a lettuce plant of lettuce cultivar 45-149RZ, representative seed of which having been deposited under NCIMB42131.

In another embodiment, the invention may comprise producing a lettuceplant having a combination of traits including resistance to downymildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837and USA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size which may comprise:crossing a mother lettuce plant with a father lettuce plant to produce ahybrid seed; growing said hybrid seed to produce a hybrid plant; selfingsaid hybrid seed to produce F2 progeny seed; selecting said F2-plantsfor exhibiting a combination of traits including resistance to downymildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837and USA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size.

Advantageously the selfing and selection may be repeated; for example atleast once, or at least twice, thrice, four times, five times, six timesor more, to produce F3 or F4 or F5 or F6 or subsequent progeny,especially as progeny from F2 may exhibit the aforementioned combinationof traits, and may be desirable.

In still a further embodiment, the invention may comprise a method ofproducing a lettuce cultivar containing a combination of traitsincluding resistance to downy mildew (Bremia lactucae) races Bl:1-28Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size.

The invention even further relates to a method of producing lettucewhich may comprise: (a) cultivating to the vegetative plant stage aplant of lettuce variety 45-149 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. NCIMB 42131, and (b) harvestinglettuce leaves or heads from the plant. The invention furthercomprehends packaging the lettuce plants, heads or leaves.

Accordingly, it is an object of the invention to not encompass withinthe invention any previously known product, process of making theproduct, or method of using the product such that Applicants reserve theright and hereby disclose a disclaimer of any previously known product,process, or method. It is further noted that the invention does notintend to encompass within the scope of the invention any product,process, or making of the product or method of using the product, whichdoes not meet the written description and enablement requirements of theUSPTO (35 U.S.C. §112, first paragraph) or the EPO (Article 83 of theEPC), such that Applicants reserve the right and hereby disclose adisclaimer of any previously described product, process of making theproduct, or method of using the product.

It is noted that in this disclosure and particularly in the claims,terms such as “comprises”, “comprised”, and “comprising” and the like(e.g., “includes”, “included”, “including”, “contains”, “contained”,“containing”, “has”, “had”, “having”, etc.) can have the meaningascribed to them in US patent law, i.e., they are open ended terms. Forexample, any method that “comprises,” “has” or “includes” one or moresteps is not limited to possessing only those one or more steps and alsocovers other unlisted steps. Similarly, any plant that “comprises,”“has” or “includes” one or more traits is not limited to possessing onlythose one or more traits and covers other unlisted traits. Similarly,the terms “consists essentially of” and “consisting essentially of” havethe meaning ascribed to them in US patent law, e.g., they allow forelements not explicitly recited, but exclude elements that are found inthe prior art or that affect a basic or novel characteristic of theinvention. See also MPEP §2111.03. In addition, the term “about” is usedto indicate that a value includes the standard deviation of error forthe device or method being employed to determine the value.

These and other embodiments are disclosed or are obvious from andencompassed by the following Detailed Description.

DEPOSIT

The Deposit with NCIMB Ltd, Ferguson Building, Craibstone Estate,Bucksburn, Aberdeen AB21 9YA, UK, on Mar. 14, 2013, under depositaccession number NCIMB 42131 was made pursuant to the terms of theBudapest Treaty. Upon issuance of a patent, all restrictions upon thedeposit will be removed, and the deposit is intended to meet therequirements of 37 CFR §§1.801-1.809. The deposit will be irrevocablyand without restriction or condition released to the public upon theissuance of a patent. The deposit will be maintained in the depositoryfor a period of 30 years, or 5 years after the last request, or for theeffective life of the patent, whichever is longer, and will be replacedif necessary during that period.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides methods and compositions relating to plants,seeds and derivatives of a new lettuce variety herein referred to aslettuce variety 45-149 RZ. Lettuce variety 45-149 RZ is a uniform andstable line, distinct from other such lines.

In a preferred embodiment, the specific type of breeding method employedfor developing a lettuce cultivar is pedigree selection, where bothsingle plant selection and mass selection practices are employed.Pedigree selection, also known as the “Vilmorin system of selection,” isdescribed in Fehr, W., Principles of Cultivar Development, Volume I,MacMillan Publishing Co., which is hereby incorporated by reference.

When pedigree selection is applied, in general selection is firstpracticed among F₂ plants. In the next season, the most desirable F₃lines are first identified, and then desirable F₃ plants within eachline are selected. The following season and in all subsequentgenerations of inbreeding, the most desirable families are identifiedfirst, then desirable lines within the selected families are chosen, andfinally desirable plants within selected lines are harvestedindividually. A family refers to lines that were derived from plantsselected from the same progeny from the preceding generation.

Using this pedigree method, two parents may be crossed using anemasculated female and a pollen donor (male) to produce F₁ offspring.Lettuce is an obligate self-pollination species, which means that pollenis shed before stigma emergence, assuring 100% self-fertilization.Therefore, in order to optimize crossing, a method of misting may beused to wash the pollen off prior to fertilization to assure crossing orhybridization.

Parental varieties are selected from commercial varieties thatindividually exhibit one or more desired phenotypes. Additionally, anybreeding method involving selection of plants for the desired phenotypemay be used in the method of the present invention.

The F₁ may be self-pollinated to produce a segregating F₂ generation.Individual plants may then be selected which represent the desiredphenotype in each generation (F₃, F₄, F₅, etc.) until the traits arehomozygous or fixed within a breeding population.

Lettuce variety 45-149 RZ was developed by crossing a plant 07V.48292with plant 07V.48015 under glasshouse conditions in Fijnaart, TheNetherlands, in 2007. In 2007 F1 plants were grown for the production ofF2 seeds, which also took place also in Fijnaart, The Netherlands. In2008, an F2 plant was selected under field conditions, again inFijnaart, followed by F3 seed production. In 2009, an F3 plant wasselected under field conditions in Fijnaart, The Netherlands, followedby F4 seed production. Subsequently in 2010, F4 plants were grown underfield conditions in Murcia, Spain, followed by F5 seed production. In2010 and 2011, a uniform F5 line was established. The F5 line was thenmultiplied under plastic tunnel conditions in Daylesford (Australia) andwas designated 11R.1404. A representative sample of seed from seedlot11R.1404 designated variety 45-149 RZ was deposited with the NCIMB underdeposit no. 42131.

In one embodiment, a plant of the invention has all the morphologicaland physiological characteristics of lettuce variety 45-149 RZ.

As used herein resistance against Bremia lactucae Regel. is defined asthe ability of a plant to resist infection by each of the variousstrains Bl:1 to Bl:28, Ca-I, Ca-IIA, Ca-IIB, Ca-III, Ca-IV, Ca-V, Ca-VI,Ca-VII, and Ca-VIII as well as strains F837 and USA927 of Bremialactucae Regel. in all stages between the seedling stage and theharvestable plant stage. Bl:1 to Bl:28 means strains NL1, NL2, NL4, NL5,NL6, NL7, NL10, NL12, NL13, NL14, NL15, NL16, Bl:7, Bl:8, Bl:20, Bl:21,Bl:22, Bl:23, Bl:24, Bl:25, Bl:26, Bl:27, Bl:28 (Van Ettekoven K, Vander Arend A J M, 1999. identification and denomination of ‘new’ races ofBremia lactucae. In: Lebeda A, Kristkova E (eds.) Eucarpia leafyvegetables '99. Palacky University, Olomouc, Czech Republic, 1999:171-175; Van der Arend, A. J. M., Gautier, J., Guenard, M., Michel, H.,Moreau, B., de Ruijter, J., Schut, J. W. and de Witte, I. (2003).Identification and denomination of ‘new’ races of Bremia lactucae inEurope by IBEB until 2002. In: Eucarpia leafy vegetables 2003.Proceedings of the Eucarpia Meeting on leafy vegetables genetics andbreeding. Noorwijkerhout, The Netherlands. Eds. Van Hintum T., LebedaA., Pink D., Schut J. pp 151-160; Van der Arend A J M, Gautier J,Grimault V, Kraan P, Van der Laan R, Mazet J, Michel H, Schut J W,Smilde D, De Witte I (2006) Identification and denomination of “new”races of Bremia lactucae in Europe by IBEB until 2006; incorporatedherein by reference; Plantum NL (Dutch association for breeding, tissueculture, production and trade of seeds and young plants), IBEB pressrelease, “New race of Bremia lactucae Bl:27 identified and nominated”,May 2010; Plantum NL (Dutch association for breeding, tissue culture,production and trade of seeds and young plants), IBEB press release,“New race of Bremia lactucae Bl:28 identified and nominated”, March2011). Ca-I to Ca-VIII means Ca-I, Ca-IIA, Ca-IIB, Ca-III, Ca-IV(Schettini, T. M., Legg, E. J., Michelmore, R. W., 1991. Insensitivityto metalaxyl in California populations of Bremia lactucae and resistanceof California lettuce cultivars to downy mildew, Phytopathology 81(1).p. 64-70), and Ca-V, Ca-VI, Ca-VII, Ca-VIII (Michelmore R. & Ochoa. O.“Breeding Crisphead Lettuce.” In: California Lettuce Research Board,Annual Report 2005-2006, 2006, Salinas, Calif., pp. 55-68). Strain F837has sextetcode EU-B 63-63-13-11 and the varieties “Steamboat”, “45-125RZ”, “45-171 RZ” and “45-21 RZ” are F837-susceptible. Strain USA927 hassextetcode EU-B 57-63-02-05 and the variety “Umbrinas” isUSA927-susceptible.

Resistance typically is tested by two interchangeable methods, describedby Bonnier, F. J. M. et al. (Euphytica, 61(3):203-211, 1992;incorporated herein by reference). One method involves inoculating 7-dayold seedlings, and observing sporulation 10 to 14 days later. The othermethod involves inoculating leaf discs with a diameter of 18 mm obtainedfrom a non-senescent, fully grown true leaf and observing sporulation 10days later.

As used herein, resistance against Nasonovia ribisnigri (Mosley), orcurrant-lettuce aphid, is defined as the plant characteristic whichresults in a non-feeding response of the aphid on the leaves of theplant in all stages between 5 true-leaf stage and harvestable plantstage (U.S. Pat. No. 5,977,443 to Jansen, J. P. A., “Aphid Resistance inComposites,” p. 12, 1999; incorporated herein by reference).

Resistance is tested by spreading at least ten aphids of biotype Nr:0 ona plant in a plant stage between 5 true leaves and harvestable stage,and observing the density of the aphid population on the plant as wellas the growth reduction after 14 days in a greenhouse, with temperaturesettings of 23 degrees Celsius in daytime and 21 degrees Celsius atnight. Day length is kept at 18 hours by assimilation lights.

As used herein, moderately glossy green leaves are defined as leaveswith a glossiness equal to or slightly more glossy than the standardvariety Salinas.

As used herein, a medium head size is a lettuce head size which is equalto or greater than the average head size of the standard varietySalinas.

In Table 1, the Bremia resistance pattern, LMV, Corky root, andNasonovia resistances as well as bolting speed, head size and leafglossiness of variety “44-149 RZ” is compared with other iceberg typelettuce varieties.

TABLE 1 45-32 RZ 45-21 RZ 45-149 RZ 45-171 RZ 45-114 RZ (Umbrinas)(Lorquinas) Nr: 0- present present present present present resistanceLMV- absent present present absent absent resistance root aphid- absentpresent present absent absent resistance (Pb) Bremia- absent absentpresent present absent F837- resistance Bremia- present present presentabsent present USA927- resistance Bolting slow very slow slow slow slowHead size medium small medium medium medium to (smaller than largeUmbrinas) Leaf Moderate Moderate dull dull dull glossiness

Embodiments of the inventions advantageously have one or more, and mostadvantageously all, of these characteristics.

In an embodiment, the invention relates to lettuce plants that has allthe morphological and physiological characteristics of the invention andhave acquired said characteristics by introduction of the geneticinformation that is responsible for the characteristics from a suitablesource, either by conventional breeding, or genetic modification, inparticular by cisgenesis or transgenesis. Cisgenesis is geneticmodification of plants with a natural gene, coding for an (agricultural)trait, from the crop plant itself or from a sexually compatible donorplant. Transgenesis is genetic modification of a plant with a gene froma non-crossable species or a synthetic gene.

Just as useful traits that may be introduced by backcrossing, usefultraits may be introduced directly into the plant of the invention, beinga plant of lettuce variety 45-149 RZ, by genetic transformationtechniques; and, such plants of lettuce variety 45-149 RZ that haveadditional genetic information introduced into the genome or thatexpress additional traits by having the DNA coding there for introducedinto the genome via transformation techniques, are within the ambit ofthe invention, as well as uses of such plants, and the making of suchplants.

Genetic transformation may therefore be used to insert a selectedtransgene into the plant of the invention, being a plant of lettucevariety 45-149 RZ or may, alternatively, be used for the preparation oftransgenes which may be introduced by backcrossing. Methods for thetransformation of plants, including lettuce, are well known to those ofskill in the art.

Vectors used for the transformation of lettuce cells are not limited solong as the vector may express an inserted DNA in the cells. Forexample, vectors which may comprise promoters for constitutive geneexpression in lettuce cells (e.g., cauliflower mosaic virus 35Spromoter) and promoters inducible by exogenous stimuli may be used.Examples of suitable vectors include pBI binary vector. The “lettucecell” into which the vector is to be introduced includes various formsof lettuce cells, such as cultured cell suspensions, protoplasts, leafsections, and callus. A vector may be introduced into lettuce cells byknown methods, such as the polyethylene glycol method, polycationmethod, electroporation, Agrobacterium-mediated transfer, particlebombardment and direct DNA uptake by protoplasts. To effecttransformation by electroporation, one may employ either friabletissues, such as a suspension culture of cells or embryogenic callus oralternatively one may transform immature embryos or other organizedtissue directly. In this technique, one would partially degrade the cellwalls of the chosen cells by exposing them to pectin-degrading enzymes(pectolyases) or mechanically wound tissues in a controlled manner.

A particularly efficient method for delivering transforming DNA segmentsto plant cells is microprojectile bombardment. In this method, particlesare coated with nucleic acids and delivered into cells by a propellingforce. Exemplary particles include those comprised of tungsten,platinum, and preferably, gold. For the bombardment, cells in suspensionare concentrated on filters or solid culture medium. Alternatively,immature embryos or other target cells may be arranged on solid culturemedium. The cells to be bombarded are positioned at an appropriatedistance below the macroprojectile stopping plate. An illustrativeembodiment of a method for delivering DNA into plant cells byacceleration is the Biolistics Particle Delivery System, which may beused to propel particles coated with DNA or cells through a screen, suchas a stainless steel or Nytex screen, onto a surface covered with targetlettuce cells. The screen disperses the particles so that they are notdelivered to the recipient cells in large aggregates. It is believedthat a screen intervening between the projectile apparatus and the cellsto be bombarded reduces the size of projectiles aggregate and maycontribute to a higher frequency of transformation by reducing thedamage inflicted on the recipient cells by projectiles that are toolarge. Microprojectile bombardment techniques are widely applicable, andmay be used to transform virtually any plant species, including a plantof lettuce variety 45-149 RZ.

Agrobacterium-mediated transfer is another widely applicable system forintroducing gene loci into plant cells. An advantage of the technique isthat DNA may be introduced into whole plant tissues, thereby bypassingthe need for regeneration of an intact plant from a protoplast.Agrobacterium transformation vectors are capable of replication in E.coli as well as Agrobacterium, allowing for convenient manipulations.Moreover, advances in vectors for Agrobacterium-mediated gene transferhave improved the arrangement of genes and restriction sites in thevectors to facilitate the construction of vectors capable of expressingvarious polypeptide coding genes. The vectors have convenientmulti-linker regions flanked by a promoter and a polyadenylation sitefor direct expression of inserted polypeptide coding genes.Additionally, Agrobacterium containing both armed and disarmed Ti genesmay be used for transformation. In those plant strains whereAgrobacterium-mediated transformation is efficient, it is the method ofchoice because of the facile and defined nature of the gene locustransfer. The use of Agrobacterium-mediated plant integrating vectors tointroduce DNA into plant cells, including lettuce plant cells, is wellknown in the art (See, e.g., U.S. Pat. Nos. 7,250,560 and 5,563,055).

Transformation of plant protoplasts also may be achieved using methodsbased on calcium phosphate precipitation, polyethylene glycol treatment,electroporation, and combinations of these treatments.

A number of promoters have utility for plant gene expression for anygene of interest including but not limited to selectable markers,scoreable markers, genes for pest tolerance, disease resistance,nutritional enhancements and any other gene of agronomic interest.Examples of constitutive promoters useful for lettuce plant geneexpression include, but are not limited to, the cauliflower mosaic virus(CaMV) P-35S promoter, a tandemly duplicated version of the CaMV 35Spromoter, the enhanced 35S promoter (P-e35S), the nopaline synthasepromoter, the octopine synthase promoter, the figwort mosaic virus(P-FMV) promoter (see U.S. Pat. No. 5,378,619), an enhanced version ofthe FMV promoter (P-eFMV) where the promoter sequence of P-FMV isduplicated in tandem, the cauliflower mosaic virus 19S promoter, asugarcane bacilliform virus promoter, a commelina yellow mottle viruspromoter, the promoter for the thylakoid membrane proteins from lettuce(psaD, psaF, psaE, PC, FNR, atpC, atpD, cab, rbcS) (see U.S. Pat. No.7,161,061), the CAB-1 promoter from lettuce (see U.S. Pat. No.7,663,027), the promoter from maize prolamin seed storage protein (seeU.S. Pat. No. 7,119,255), and other plant DNA virus promoters known toexpress in plant cells. A variety of plant gene promoters that areregulated in response to environmental, hormonal, chemical, and/ordevelopmental signals may be used for expression of an operably linkedgene in plant cells, including promoters regulated by (1) heat, (2)light (e.g., pea rbcS-3A promoter, maize rbcS promoter, or chlorophylla/b-binding protein promoter), (3) hormones, such as abscisic acid, (4)wounding (e.g., wunl, or (5) chemicals such as methyl jasmonate,salicylic acid, or Safener. It may also be advantageous to employorgan-specific promoters.

Exemplary nucleic acids which may be introduced to the lettuce varietyof this invention include, for example, DNA sequences or genes fromanother species, or even genes or sequences which originate with or arepresent in lettuce species, but are incorporated into recipient cells bygenetic engineering methods rather than classical reproduction orbreeding techniques. However, the term “exogenous” is also intended torefer to genes that are not normally present in the cell beingtransformed, or perhaps simply not present in the form, structure, etc.,as found in the transforming DNA segment or gene, or genes which arenormally present and that one desires to express in a manner thatdiffers from the natural expression pattern, e.g., to over-express.Thus, the term “exogenous” gene or DNA is intended to refer to any geneor DNA segment that is introduced into a recipient cell, regardless ofwhether a similar gene may already be present in such a cell. The typeof DNA included in the exogenous DNA may include DNA which is alreadypresent in the plant cell, DNA from another plant, DNA from a differentorganism, or a DNA generated externally, such as a DNA sequencecontaining an antisense message of a gene, or a DNA sequence encoding asynthetic or modified version of a gene.

Many hundreds if not thousands of different genes are known and couldpotentially be introduced into a plant of lettuce variety 45-149 RZ.Non-limiting examples of particular genes and corresponding phenotypesone may choose to introduce into a lettuce plant include one or moregenes for insect tolerance, pest tolerance such as genes for fungaldisease control, herbicide tolerance, and genes for quality improvementssuch as yield, nutritional enhancements, environmental or stresstolerances, or any desirable changes in plant physiology, growth,development, morphology or plant product(s).

Alternatively, the DNA coding sequences may affect these phenotypes byencoding a non-translatable RNA molecule that causes the targetedinhibition of expression of an endogenous gene, for example viaantisense- or cosuppression-mediated mechanisms. The RNA could also be acatalytic RNA molecule (i.e., a ribozyme) engineered to cleave a desiredendogenous mRNA product. Thus, any gene which produces a protein or mRNAwhich expresses a phenotype or morphology change of interest is usefulfor the practice of the present invention. (See also U.S. Pat. No.7,576,262, “Modified gene-silencing RNA and uses thereof.”)

U.S. Pat. Nos. 7,230,158, 7,122,720, 7,081,363, 6,734,341, 6,503,732,6,392,121, 6,087,560, 5,981,181, 5,977,060, 5,608,146, 5,516,667, eachof which, and all documents cited therein are hereby incorporated hereinby reference, consistent with the above INCORPORATION BY REFERENCEsection, are additionally cited as examples of U.S. patents that mayconcern transformed lettuce and/or methods of transforming lettuce orlettuce plant cells, and techniques from these US patents, as well aspromoters, vectors, etc., may be employed in the practice of thisinvention to introduce exogenous nucleic acid sequence(s) into a plantof lettuce variety 45-149 RZ (or cells thereof), and exemplify someexogenous nucleic acid sequence(s) which may be introduced into a plantof lettuce variety 45-149 RZ (or cells thereof) of the invention, aswell as techniques, promoters, vectors etc., to thereby obtain furtherplants of lettuce variety 45-149 RZ, plant parts and cells, seeds, otherpropagation material harvestable parts of these plants, etc. of theinvention, e.g. tissue culture, including a cell or protoplast, such asan embryo, meristem, cotyledon, pollen, leaf, anther, root, root tip,pistil, flower, seed or stalk.

The invention further relates to propagation material for producingplants of the invention. Such propagation material may comprise interalia seeds of the claimed plant and parts of the plant that are involvedin sexual reproduction. Such parts are for example selected from thegroup consisting of seeds, microspores, pollen, ovaries, ovules, embryosacs and egg cells. In addition, the invention relates to propagationmaterial which may comprise parts of the plant that are suitable forvegetative reproduction, for example cuttings, roots, stems, cells,protoplasts.

According to a further aspect thereof the propagation material of theinvention may comprise a tissue culture of the claimed plant. The tissueculture may comprise regenerable cells. Such tissue culture may bederived from leaves, pollen, embryos, cotyledon, hypocotyls,meristematic cells, roots, root tips, anthers, flowers, seeds and stems.(See generally U.S. Pat. No. 7,041,876 on lettuce being recognized as aplant that may be regenerated from cultured cells or tissue).

Also, the invention comprehends methods for producing a seed of a“45-149 RZ”-derived lettuce plant which may comprise (a) crossing aplant of lettuce variety 45-149 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. NCIMB 42131, with a secondlettuce plant, and (b) whereby seed of a 45-149 RZ-derived lettuce plantform (e.g., by allowing the plant from the cross to grow to producingseed). Such a method may further comprise (c) crossing a plant grownfrom 45-149 RZ-derived lettuce seed with itself or with a second lettuceplant to yield additional 45-149 RZ-derived lettuce seed, (d) growingthe additional 45-149 RZ-derived lettuce seed of step (c) to yieldadditional 45-149 RZ-derived lettuce plants and selecting plantsexhibiting a combination of the traits including resistance to downymildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837and USA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size, and (e) repeating thecrossing and growing of steps (c) and (d) for an additional 3-10generations to further generate 45-149 RZ-derived lettuce plants thatexhibits a combination of traits including resistance to downy mildew(Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 andUSA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size.

The invention further relates to the above methods that further compriseselecting at steps b), d), and e), a 45-149 RZ-derived lettuce plant,exhibiting a combination of traits including resistance to downy mildew(Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 andUSA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size. In particular, theinvention relates to methods for producing a seed of a 45-149 RZ-derivedlettuce plant which may comprise (a) crossing a plant of lettuce variety45-149 RZ, representative seed of which having been deposited underNCIMB Accession No. NCIMB 42131, with a second lettuce plant and (b)whereby seed of a 45-149 RZ-derived lettuce plant forms, wherein such amethod may further comprise (c) crossing a plant grown from 45-149RZ-derived lettuce seed with itself or with a second lettuce plant toyield additional 45-149 RZ-derived lettuce seed, (d) growing theadditional 45-149 RZ-derived lettuce seed of step (c) to yieldadditional 45-149 RZ-derived lettuce plants and selecting plantsexhibiting a combination of the traits including resistance to downymildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837and USA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size, and (e) repeating thecrossing and growing of steps (c) and (d) for an additional 3-10generations to further generate 45-149 RZ-derived lettuce plants thatexhibit a combination of traits including resistance to downy mildew(Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 andUSA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size.

The invention additionally provides a method of introducing a desiredtrait into a plant of lettuce variety 45-149 RZ which may comprise: (a)crossing a plant of lettuce variety 45-149 RZ, representative seed ofwhich having been deposited under NCIMB Accession No. NCIMB 42131, witha second lettuce plant that may comprise a desired trait to produce F1progeny; (b) selecting an F1 progeny that may comprise the desiredtrait; (c) crossing the selected F1 progeny with a plant of lettucevariety 45-149 RZ, to produce backcross progeny; (d) selecting backcrossprogeny which may comprise the desired trait and the physiological andmorphological characteristic of a plant of lettuce variety 45-149 RZ;and, optionally, (e) repeating steps (c) and (d) one or more times insuccession to produce selected fourth or higher backcross progeny thatcomprise the desired trait and all of the physiological andmorphological characteristics of a plant of lettuce variety 45-149 RZ,when grown in the same environmental conditions. The invention, ofcourse, includes a lettuce plant produced by this method.

Backcrossing may also be used to improve an inbred plant. Backcrossingtransfers a specific desirable trait from one inbred or non-inbredsource to an inbred that lacks that trait. This may be accomplished, forexample, by first crossing a superior inbred (A) (recurrent parent) to adonor inbred (non-recurrent parent), which carries the appropriate locusor loci for the trait in question. The progeny of this cross are thenmated back to the superior recurrent parent (A) followed by selection inthe resultant progeny for the desired trait to be transferred from thenon-recurrent parent. After five or more backcross generations withselection for the desired trait, the progeny are heterozygous for locicontrolling the characteristic being transferred, but are like thesuperior parent for most or almost all other loci. The last backcrossgeneration would be selfed to give pure breeding progeny for the traitbeing transferred. When a plant of lettuce variety 45-149 RZ,representative seed of which having been deposited under NCIMB AccessionNo. NCIMB 42131, is used in backcrossing, offspring retaining thecombination of traits including resistance to downy mildew (Bremialactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927,resistance to currant-lettuce aphid (Nasonovia ribisnigri), moderatelyglossy leaves, and a medium head size are progeny within the ambit ofthe invention. Backcrossing methods may be used with the presentinvention to improve or introduce a characteristic into a plant of theinvention, being a plant of lettuce variety 45-149 RZ. See, e.g., U.S.Pat. No. 7,705,206 (incorporated herein by reference consistent with theabove INCORPORATION BY REFERENCE section), for a general discussionrelating to backcrossing.

The invention further involves a method of determining the genotype of aplant of lettuce variety 45-149 RZ, representative seed of which hasbeen deposited under NCIMB Accession No. NCIMB 42131, or a firstgeneration progeny thereof, which may comprise obtaining a sample ofnucleic acids from said plant and detecting in said nucleic acids aplurality of polymorphisms. This method may additionally comprise thestep of storing the results of detecting the plurality of polymorphismson a computer readable medium. The plurality of polymorphisms areindicative of and/or give rise to the expression of the morphologicaland physiological characteristics of lettuce variety 45-149 RZ. Thereare various ways of obtaining genotype data from a nucleic acid sample.Genotype data may be gathered which is specific for certain phenotypictraits (e.g. gene sequences), but also patterns of random geneticvariation may be obtained to construct a so-called DNA fingerprint.Depending on the technique used a fingerprint may be obtained that isunique for lettuce variety 45-149 RZ. Obtaining a unique DNA fingerprintdepends on the genetic variation present in a variety and thesensitivity of the fingerprinting technique. A technique known in theart to provide a good fingerprint profile is called AFLP fingerprintingtechnique (See generally U.S. Pat. No. 5,874,215), but there are manyother marker based techniques, such as RFLP (or Restriction fragmentlength polymorphism), SSLP (or Simple sequence length polymorphism),RAPD (or Random amplification of polymorphic DNA) VNTR (or Variablenumber tandem repeat), Microsatellite polymorphism, SSR (or Simplesequence repeat), STR (or Short tandem repeat), SFP (or Single featurepolymorphism) DArT (or Diversity Arrays Technology), RAD markers (orRestriction site associated DNA markers) (e.g. Baird et al. PloS OneVol. 3 e3376, 2008; Semagn et al. African Journal of Biotechnology Vol.5 number 25 pp. 2540-2568, 29 December, 2006). Nowadays, sequence-basedmethods are utilizing Single Nucleotide Polymorphisms (SNPs) that arerandomly distributed across genomes, as a common tool for genotyping(e.g. Elshire et al. PloS One Vol. 6: e19379, 2011; Poland et al. PloSOne Vol. 7: e32253; Truong et al. PLoS One Vol. 7 number 5: e37565,2012).

With any of the aforementioned genotyping techniques, polymorphisms maybe detected when the genotype and/or sequence of the plant of interestis compared to the genotype and/or sequence of one or more referenceplants. As used herein, the genotype and/or sequence of a referenceplant may be derived from, but is not limited to, any one of thefollowing: parental lines, closely related plant varieties or species,complete genome sequence of a related plant variety or species, or thede novo assembled genome sequence of one or more related plant varietiesor species. For example, it is possible to detect polymorphisms for thecharacteristics of Bremia resistance or leaf glossiness by comparing thegenotype and/or the sequence of lettuce variety 45-149 RZ with thegenotype and/or the sequence of one or more reference plants. Thereference plant(s) used for comparison may for example be, but is notlimited to, any of the varieties mentioned in Table 1 or even wildrelatives such as Lactuca serriola accessions.

The polymorphism revealed by these techniques may be used to establishlinks between genotype and phenotype. The polymorphisms may thus be usedto predict or identify certain phenotypic characteristics, individuals,or even species. The polymorphisms are generally called markers. It iscommon practice for the skilled artisan to apply molecular DNAtechniques for generating polymorphisms and creating markers.

The polymorphisms of this invention may be provided in a variety ofmediums to facilitate use, e.g. a database or computer readable medium,which may also contain descriptive annotations in a form that allows askilled artisan to examine or query the polymorphisms and obtain usefulinformation.

As used herein “database” refers to any representation of retrievablecollected data including computer files such as text files, databasefiles, spreadsheet files and image files, printed tabulations andgraphical representations and combinations of digital and image datacollections. In a preferred aspect of the invention, “database” refersto a memory system that may store computer searchable information.

As used herein, “computer readable media” refers to any medium that maybe read and accessed directly by a computer. Such media include, but arenot limited to: magnetic storage media, such as floppy discs, hard disc,storage medium and magnetic tape; optical storage media such as CD-ROM;electrical storage media such as RAM, DRAM, SRAM, SDRAM, ROM; and PROMs(EPROM, EEPROM, Flash EPROM), and hybrids of these categories such asmagnetic/optical storage media. A skilled artisan may readily appreciatehow any of the presently known computer readable mediums may be used tocreate a manufacture which may comprise computer readable medium havingrecorded thereon a polymorphism of the present invention.

As used herein, “recorded” refers to the result of a process for storinginformation in a retrievable database or computer readable medium. Forinstance, a skilled artisan may readily adopt any of the presently knownmethods for recording information on computer readable medium togenerate media which may comprise the polymorphisms of the presentinvention. A variety of data storage structures are available to askilled artisan for creating a computer readable medium where the choiceof the data storage structure will generally be based on the meanschosen to access the stored information. In addition, a variety of dataprocessor programs and formats may be used to store the polymorphisms ofthe present invention on computer readable medium.

The present invention further provides systems, particularlycomputer-based systems, which contain the polymorphisms describedherein. Such systems are designed to identify the polymorphisms of thisinvention. As used herein, “a computer-based system” refers to thehardware, software and memory used to analyze the polymorphisms. Askilled artisan may readily appreciate that any one of the currentlyavailable computer-based system are suitable for use in the presentinvention.

Lettuce leaves are sold in packaged form, including without limitationas pre-packaged lettuce salad or as lettuce heads. Mention is made ofU.S. Pat. No. 5,523,136, incorporated herein by reference consistentwith the above INCORPORATION BY REFERENCE section, which providespackaging film, and packages from such packaging film, including suchpackaging containing leafy produce, and methods for making and usingsuch packaging film and packages, which are suitable for use with thelettuce leaves of the invention. Thus, the invention comprehends the useof and methods for making and using the leaves of the lettuce plant ofthe invention, as well as leaves of lettuce plants derived from theinvention. The invention further relates to a container which maycomprise one or more plants of the invention, or one or more lettuceplants derived from a plant of the invention, in a growth substrate forharvest of leaves from the plant in a domestic environment. This way theconsumer may pick very fresh leaves for use in salads. More generally,the invention includes one or more plants of the invention or one ormore plants derived from lettuce of the invention, wherein the plant isin a ready-to-harvest condition, including with the consumer picking hisown, and further including a container which may comprise one or more ofthese plants.

The invention is further described by the following numbered paragraphs:

1. Lettuce plant exhibiting a combination of traits including resistanceto downy mildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, andstrains F837 and USA927, resistance to currant-lettuce aphid (Nasonoviaribisnigri), moderately glossy leaves, and a medium head size,representative seed of which having been deposited under NCIMB AccessionNo. 42131.

2. Lettuce plant designated 45-149 RZ, representative seed of whichhaving been deposited under NCIMB Accession No. 42131.

3. A seed of the plant of paragraph 1.

4. Parts of the plant of paragraph 1 or paragraph 2, wherein said partsof the plant are suitable for sexual reproduction.

5. Parts of the plant as described in paragraph 4, wherein said partsare selected from the group consisting of microspores, pollen, ovaries,ovules, embryo sacs and egg cells.

6. Parts of the plant of paragraph 1 or paragraph 2, wherein said partsof the plant are suitable for vegetative reproduction.

7. Parts as described in paragraph 6, wherein said parts are selectedfrom the group consisting of cuttings, roots, stems, cells andprotoplasts.

8. A tissue culture of regenerable cells from the lettuce plant ofparagraph 1.

9. A tissue culture as described in paragraph 9, wherein said cells orprotoplasts of the tissue culture which are derived from a tissueselected from the group consisting of leaves, pollen, embryos,cotyledon, hypocotyls, meristematic cells, roots, root tips, anthers,flowers, seeds and stems.

10. Progeny of a lettuce plant of paragraph 1 or paragraph 2.

11. Progeny as described in paragraph 10, wherein said progeny isproduced by sexual or vegetative reproduction of said lettuce plant, andwherein said progeny exhibits a combination of traits includingresistance to downy mildew (Bremia lactucae) races Bl:1-28 Ca-I toCa-VIII, and strains F837 and USA927, resistance to currant-lettuceaphid (Nasonovia ribisnigri), moderately glossy leaves, and a mediumhead size.

12. Progeny of a lettuce plant of paragraph 2, having all themorphological and physiological characteristics of the lettuce plant ofparagraph 2, representative seed of which having been deposited underNCIMB Accession No. 42131 wherein as found in lettuce variety 45-149 RZ,representative seed of which having been deposited under NCIMB AccessionNo. 42131.

13. Progeny of a lettuce plant of paragraph 1 or paragraph 2,representative seed of which having been deposited under NCIMB Accession42131, and is modified in one or more other characteristics.

14. Progeny as described in paragraph 13, wherein the modification iseffected by mutagenesis.

15. Progeny as described in paragraph 13, wherein the modification iseffected by transformation with a transgene.

16. A method of producing a hybrid lettuce seed comprising crossing afirst parent lettuce plant with a second parent lettuce plant andharvesting the resultant hybrid lettuce seed, wherein said first parentlettuce plant or said second parent lettuce plant is the lettuce plantof paragraph 1.

17. A hybrid lettuce plant produced by the method of paragraph 16.

18. A method of producing a lettuce cultivar containing a combination oftraits including resistance to downy mildew (Bremia lactucae) racesBl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size, comprising: crossing a mother lettuce plant witha father lettuce plant to produce a hybrid seed; growing said hybridseed to produce a hybrid plant; selfing said hybrid seed to produce F2progeny seed; selecting said F2-plants for exhibiting resistance todowny mildew (Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, andstrains F837 and USA927, resistance to currant-lettuce aphid (Nasonoviaribisnigri), moderately glossy leaves, and a medium head size, and,selfing said selected F2-plants to produce F3 progeny seed; selectingF3-plants for exhibiting resistance to downy mildew (Bremia lactucae)races Bl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistanceto currant-lettuce aphid (Nasonovia ribisnigri), moderately glossyleaves, and a medium head size, optionally followed by more selfing andselection steps.

19. A lettuce cultivar produced by the method of paragraph 18.

20. A method for producing lettuce leaves as a fresh vegetablecomprising packaging leaves of a plant of paragraph 1.

21. A method for producing lettuce leaves as a processed food comprisingprocessing leaves of a plant of paragraph 1.

22. One or more lettuce plants of paragraph 1, in a container, forharvest of leaves.

23. Lettuce plant having morphological and/or physiologicalcharacteristics of a lettuce plant, representative seed of which havingbeen deposited under NCIMB Accession No. 42131.

24. Lettuce plant of paragraph 22 having all the morphological andphysiological characteristics of the lettuce plant, representative seedof which having been deposited under NCIMB Accession No. 42131.

25. A method of introducing a desired trait into a plant of lettucevariety 45-149 RZ comprising: (a) crossing a plant of lettuce variety45-149 RZ, representative seed of which having been deposited underNCIMB Accession No. NCIMB 42131, with a second lettuce plant thatcomprises the desired trait to produce F1 progeny; (b) selecting an F1progeny that comprises the desired trait; (c) crossing the selected F1progeny with a plant of lettuce variety 45-149 RZ, to produce backcrossprogeny and (d) selecting backcross progeny comprising the desired traitand the physiological and morphological characteristic of a plant oflettuce variety 45-149 RZ, when grown in the same environmentalconditions.

26. The method of paragraph 25 further comprising (e) repeating steps(c) and (d) one or more times in succession to produce selected fourthor higher backcross progeny that comprise the desired trait and all ofthe physiological and morphological characteristics of a plant oflettuce variety 45-149 RZ, when grown in the same environmentalconditions.

27. A lettuce plant produced by the method of paragraph 25 or paragraph26.

28. A method for producing a seed of a 45-149 RZ-derived lettuce plantcomprising (a) crossing a plant of lettuce variety 45-149 RZ,representative seed of which having been deposited under NCIMB AccessionNo. NCIMB 42131, with a second lettuce plant, and (b) whereby seed of a45-149 RZ-derived lettuce plant form.

29. The method of paragraph 28 further comprising (c) crossing a plantgrown from 45-149 RZ-derived lettuce seed with itself or with a secondlettuce plant to yield additional 45-149 RZ-derived lettuce seed, (d)growing the additional 45-149 RZ-derived lettuce seed of step (c) toyield additional 45-149 RZ-derived lettuce plants, and (e) repeating thecrossing and growing of steps (c) and (d) for an additional 3-10generations to generate further 45-149 RZ-derived lettuce plants.

30. The method of paragraph 28 or 29 further comprising selecting atsteps b), d), and e), a 45-149 RZ-derived lettuce plant, exhibiting acombination of traits including resistance to downy mildew (Bremialactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927,resistance to currant-lettuce aphid (Nasonovia ribisnigri), moderatelyglossy leaves, and a medium head size.

31. Seed produced by the method of paragraphs 28, or paragraph 29, orparagraph 30.

32. A method of determining the genotype of a plant of lettuce variety45-149 RZ, representative seed of which has been deposited under NCIMBAccession No. NCIMB 42131, or a first generation progeny thereof,comprising obtaining a sample of nucleic acids from said plant andcomparing said nucleic acids to a sample of nucleic acids obtained froma reference plant, and detecting a plurality of polymorphisms betweenthe two nucleic acid samples, wherein the plurality of polymorphisms areindicative of lettuce variety 45-149 RZ and/or give rise to theexpression of any one or more, or all, of the morphological andphysiological characteristics of lettuce variety 45-149 RZ as describedin paragraph 1.

33. The method of paragraph 32 additionally comprising the step ofstoring the results of detecting the plurality of polymorphisms on acomputer readable medium, or transmitting the results of detecting theplurality of polymorphisms.

34. The computer readable medium of paragraph 33.

Having thus described in detail preferred embodiments of the presentinvention, it is to be understood that the invention is not to belimited to particular details set forth in the above description as manyapparent variations thereof are possible without departing from thespirit or scope of the present invention.

What is claimed is:
 1. An iceberg lettuce plant exhibiting a combinationof traits including resistance to downy mildew (Bremia lactucae) racesBl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size, representative seed of which having beendeposited under NCIMB Accession No.
 42131. 2. A seed of the plant ofclaim
 1. 3. A part of the plant of claim 1, wherein said part of theplant is suitable for sexual reproduction.
 4. The part of the plant asclaimed in claim 3, wherein said part comprises a microspore, pollen,ovary, ovule, embryo sac or egg cell.
 5. A part of the plant of claim 1,wherein said part of the plant is suitable for vegetative reproduction.6. The part as claimed in claim 5, wherein said part comprises acutting, root, stem, cell or protoplast.
 7. A tissue culture ofregenerable cells or protoplasts from the lettuce plant of claim
 1. 8.The tissue culture as claimed in claim 7, wherein said cells orprotoplasts of the tissue culture are derived from a tissue comprising aleaf, pollen, embryo, cotyledon, hypocotyl, meristematic cell, root,root tip, anther, flower, seed or stem.
 9. A progeny of a lettuce plantof claim 1, wherein the progeny exhibits the combination of traits ofthe lettuce plant of claim
 1. 10. The progeny as claimed in claim 9,wherein said progeny is produced by sexual or vegetative reproduction ofsaid lettuce plant, and wherein said progeny exhibits a combination oftraits including resistance to downy mildew (Bremia lactucae) racesBl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size.
 11. A progeny of a lettuce plant of claim 1,representative seed of which having been deposited under NCIMB Accession42131, wherein the progeny exhibits the combination of traits of thelettuce plant of claim 1 and the progeny is further modified in one ormore other characteristics.
 12. The progeny as claimed in claim 11,wherein the modification is effected by mutagenesis.
 13. The progeny asclaimed in claim 11, wherein the modification is effected bytransformation with a transgene.
 14. A method of producing a hybridlettuce seed comprising crossing a first parent lettuce plant with asecond parent lettuce plant and harvesting the resultant hybrid lettuceseed, wherein said first parent lettuce plant or said second parentlettuce plant is the lettuce plant of claim
 1. 15. A hybrid lettuce seedproduced by the method of claim
 14. 16. A hybrid lettuce plant grownfrom the seed of claim
 15. 17. A method for producing lettuce leaves asa fresh vegetable comprising packaging leaves of a plant of claim
 1. 18.A method for producing lettuce leaves as a processed food comprisingprocessing leaves of a plant of claim
 1. 19. A lettuce plant having thecombination of traits of the lettuce plant of claim 1 and othermorphological and/or physiological characteristics of a lettuce plant,representative seed of which having been deposited under NCIMB AccessionNo.
 42131. 20. The lettuce plant of claim 19 having all themorphological and physiological characteristics of the lettuce plant,representative seed of which having been deposited under NCIMB AccessionNo.
 42131. 21. A method of determining the genotype of a plant oflettuce variety 45-149 RZ, representative seed of which has beendeposited under NCIMB Accession No. 42131, or a first generation progenythereof, comprising obtaining a sample of nucleic acids from said plantand comparing said nucleic acids to a sample of nucleic acids obtainedfrom a reference plant, and detecting a plurality of polymorphismsbetween the two nucleic acid samples, wherein the plurality ofpolymorphisms are indicative of lettuce variety 45-149 RZ and/or giverise to the expression of any one or more, or all, of the morphologicaland physiological characteristics of lettuce variety 45-149 RZ asclaimed in claim
 1. 22. The method of claim 21 additionally comprisingthe step of storing the results of detecting the plurality ofpolymorphisms on a computer readable medium, or transmitting the resultsof detecting the plurality of polymorphisms.
 23. A lettuce plantdesignated 45-149 RZ, representative seed of which having been depositedunder NCIMB Accession No.
 42131. 24. A progeny of a lettuce plant ofclaim 23, having all the morphological and physiological characteristicsof the lettuce plant of claim 23, wherein the morphological andphysiological characteristics are as found in lettuce variety 45-149 RZ,representative seed of which having been deposited under NCIMB AccessionNo.
 42131. 25. The lettuce plant of claim 23, which is a plant grownfrom seed having been deposited under NCIMB Accession No.
 42131. 26. Amethod of producing a lettuce cultivar containing a combination oftraits including resistance to downy mildew (Bremia lactucae) racesBl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size, representative seed of which having beendeposited under NCIMB Accession No. 42131, comprising: crossing a motherlettuce plant with a father lettuce plant to produce a hybrid seed;growing said hybrid seed to produce a hybrid plant; selfing said hybridseed to produce F2 progeny seed; selecting said F2-plants for exhibitingresistance to downy mildew (Bremia lactucae) races Bl:1-28 Ca-I toCa-VIII, and strains F837 and USA927, resistance to currant-lettuceaphid (Nasonovia ribisnigri), moderately glossy leaves, and a mediumhead size, and, selfing said selected F2-plants to produce F3 progenyseed; selecting F3-plants for exhibiting resistance to downy mildew(Bremia lactucae) races Bl:1-28 Ca-I to Ca-VIII, and strains F837 andUSA927, resistance to currant-lettuce aphid (Nasonovia ribisnigri),moderately glossy leaves, and a medium head size, representative seed ofwhich having been deposited under NCIMB Accession No. 42131, optionallyfollowed by more selfing and selection steps.
 27. A lettuce cultivarproduced by the method of claim
 26. 28. A method of introducing adesired trait into a plant of lettuce variety 45-149 RZ comprising: (a)crossing a plant of lettuce variety 45-149 RZ, representative seed ofwhich having been deposited under NCIMB Accession No. NCIMB 42131, witha second lettuce plant that comprises the desired trait to produce F1progeny; (b) selecting an F1 progeny that comprises the desired trait;(c) crossing the selected F1 progeny with a plant of lettuce variety45-149 RZ, to produce backcross progeny and (d) selecting backcrossprogeny comprising the desired trait and the physiological andmorphological characteristic of a plant of lettuce variety 45-149 RZ,when grown in the same environmental conditions.
 29. The method of claim28 further comprising (e) repeating steps (c) and (d) one or more timesin succession to produce selected fourth or higher backcross progenythat comprise the desired trait and all of the physiological andmorphological characteristics of a plant of lettuce variety 45-149 RZ,when grown in the same environmental conditions.
 30. A lettuce plantproduced by the method of claim
 28. 31. A method for producing a seed ofa 45-149 RZ-derived lettuce plant comprising (a) crossing a plant oflettuce variety 45-149 RZ, representative seed of which having beendeposited under NCIMB Accession No. NCIMB 42131, with a second lettuceplant, and (b) whereby seed of a 45-149 RZ-derived lettuce plant form.32. The method of claim 31 further comprising (c) crossing a plant grownfrom 45-149 RZ-derived lettuce seed with itself or with a second lettuceplant to yield additional 45-149 RZ-derived lettuce seed, (d) growingthe additional 45-149 RZ-derived lettuce seed of step (c) to yieldadditional 45-149 RZ-derived lettuce plants, and (e) repeating thecrossing and growing of steps (c) and (d) for an additional 3-10generations to generate further 45-149 RZ-derived lettuce plants. 33.The method of claim 32 further comprising selecting at steps b), d), ande), a 45-149 RZ-derived lettuce plant, exhibiting a combination oftraits including resistance to downy mildew (Bremia lactucae) racesBl:1-28 Ca-I to Ca-VIII, and strains F837 and USA927, resistance tocurrant-lettuce aphid (Nasonovia ribisnigri), moderately glossy leaves,and a medium head size.
 34. A seed produced by the method of claim 31.35. A lettuce plant exhibiting a combination of traits includingresistance to downy mildew (Bremia lactucae) races Bl:1-28 Ca-I toCa-VIII, and strains F837 and USA927, resistance to currant-lettuceaphid (Nasonovia ribisnigri), moderately glossy leaves, and a mediumhead size, and having genetic information for so exhibiting thecombination of traits, wherein the genetic information is as containedin a plant representative seed of which having been deposited underNCIMB Accession No. 42131.